3. Blueberries

Too tired to concentrate? When it comes to increasing brain function, mental tasks and cognitive performance, blueberries should be your weapon of choice. A study published in the Annals of Neurology suggests that antioxidant-rich blueberries can reduce cognitive decline in older adults by up to 2.5 years. What makes the blueberries blue are polyphenol pigments called anthocyanins, which are anti-inflammatory and antioxidant. Anthocyanins are associated with increased neural signaling in the brain, especially around the areas that affect memory function. Blueberries also contain resveratrol, the compound that made red wine an overnight health sensation. If fresh berries are out of season or too expensive, buy frozen ones — they retain virtually all the same nutrients and health benefits. And don’t worry about the sugar content. Blueberries have a very low glycemic load and are handled well by diabetics. Besides, eating more blueberries will help your memory, so you won’t forget to buy more blueberries!